As much as people want a single, definitive answer to this subject, you're not gonna get it. There too many variables. Phone books, ballistic gelatin, monkey butts, whatever. Go to "The Box-O-Truth" web site and get some good info. However, they shoot drywall set in frames only a couple inches apart, and show that penetration. If you shoot in a dwelling/structure, those walls are farther apart, allowing for greater deceleration of the projectiles before hitting the next barrier.
00 buck pellets will maintain greater energy and greater penetration than smaller pellets. I would suggest suggest #4 buck or #2 game loads in your house as you will be in a close quarters situation where those loads will be very effective but less likely to hit your family & neighbors. Check Box-o-Truth as they fire Glaser rounds to see my point. The round begins to fragment in the first board, but it is still in a tighter mass as it hits the next boards. I've fired those rounds in a house, and as it fragments exiting the first wall it's energy drops quickly. Kind of like getting peppered with #7 or 8 shot from another dove hunter some distance away.